1. Field of the Invention
The present invention relates generally to a branch apparatus for a pipe and a branch method using the same which connect a branch pipe installed to a place requiring a such as a gas, a chemical substance and water to a main pipe through which the fluid flows. More particularly, it relates to a branch apparatus for a pipe and a branch method using the same which make a laying depth of the main pipe be identical with that of the branch pipe by horizontally installing a branch apparatus, and thus make the branch pipe receive a low vibration and a small load from the ground.
2. Description of the Related Art
In recent years, most homes use a liquefied natural gas (LNG) as a household fuel, and buildings and houses mostly use the LNG as a fuel of a heating device. Accordingly, there are many gas pipes for supplying each home and building with LNG under the ground of all cities and villages, and the gas pipes are complexly laid like cobwebs.
Water supply and drainage pipes as well as the gas pipes are also laid under the ground of all residences. Pipes for transmitting a chemical substance to a desired place are laid under a factory for manufacturing a chemical substance. A main pipe through which flows a fluid such as the gas, chemical substance and water is connected to a branch pipe installed to a place requiring the fluid by using the branch apparatus, thus the fluid becomes used at the desired place.
If the fluid is the gas, to convey LNG from the main pipe to a building or house, a branch pipe connected from the main pipe to the building or house is first laid, and finally the main pipe is connected to the branch pipe by using the branch apparatus.
As shown in FIGS. 1 and 2, the conventional branch apparatus 1 for connecting the main pipe to the branch pipe is vertically mounted, whereby a main pipe 2 is connected to a branch pipe 3. Since the branch pipe 3 is positioned at a position higher than the main pipe 2, the branch pipe 3 receives a large load and vibration from the ground, and the branch pipe 3 is easily exposed to the outside during a road repair work, thereby the branch pipe 3 being easily damaged.
In case of using the gas pipe, a depth for laying the gas pipe under the ground is generally prescribed. A laying depth of gas pipe is prescribed to 1.2 meter(s) at a road having a width over 8 meter(s), to 1.0 meter(s) at a road having a width below 8 meter(s), and to 0.6 meter(s) at the residential areas.
As shown in FIG. 2, the gas pipe is buried in both an auxiliary stratum made of sand and gravel and outer stratum made of asphalt pavement. Although it is desirable that the main pipe 2 and the branch pipe 3 are laid at the same depth, he branch pipe 3 should be laid at a higher position than the main pipe 2 because the conventional branch apparatus 1 is a vertical type. A structure of a conventional vertical-type branch apparatus and a branch method using the same will now be described below.
As shown in FIGS. 3 and 4, the conventional vertical-type branch apparatus includes: a T-type pipe 11 having a branch pipe coupling member 11a; a reinforcement plate 12 welded to a lower part of the T-type pipe 11, an inner diameter curvature of which is identical with an outer diameter curvature of the main pipe 2; a flange 13 which is welded an upper part of the T-type pipe 11, and has female screw lines in its center; a plug 14 coupled with the center of the flange 13; a cover 15 coupled with the flange 13; and bolts 16 and nuts 17 for coupling the flange 14 with the cover 15. The branch method for connecting the main pipe 2 and the branch pipe 3 by using the vertical-type branch apparatus will now be described below.
In a first step, referring to FIGS. 1 to 5, the reinforcement plate 12 of the branch apparatus is vertically laid on the main pipe 2 and then welded, and the branch pipe coupling member 11a of the T-type pipe 11 is welded to the branch pipe 3.
In a second step, after a cut-off valve 4 is mounted to an upper part of the flange 13, a piercing machine 8 is mounted to an upper part of the cut-off valve 4.
In a third step, as shown in FIG. 5, the cut-off valve 4 is opened, a saw portion 9 of the piercing machine 8 is descended toward the main pipe 2, and then the saw portion 9 rotates, thereby piercing the main pipe 2.
In a fourth step, the saw portion 9 of the piercing machine 8 and a cut portion 10 of the main pipe 2 are elevated in a main body of the piercing machine 8. The piercing machine 8 has an apparatus for simultaneously elevating the cut portion 10 and the saw portion 9, but this apparatus has no relation with the present invention, so that a description regarding this apparatus is omitted.
In a fifth step, the cut-off valve 4 is closed, the piercing machine 8 is removed from the cut-off valve 4.
In a sixth step, as shown in FIG. 6, a plug adapter 8a is connected to the piercing machine 8, the plug 14 is connected to the plug adapter 8a, and the piercing machine 8 is mounted again to the cut-off valve 4. In a seventh step, the cut-off valve 4 is opened, the piercing machine 8 is then operated, thus the plug 14 is screw-connected to the flange 13.
In an eighth step, after the piercing machine 8 and the cut-off valve 4 are removed from the flange 13, the cover 15 is connected to the flange 13 by using the bolts 16 and nuts 17. As described above, according to the conventional vertical-type branch apparatus and a branch method using this branch apparatus, since the branch pipe 3 is positioned at a position higher than the main pipe 2, the branch pipe 3 receives a large load and vibration from the ground, and thus a crack may occur in the vicinity of a welding portion. Also, since the branch pipe 3 is easily exposed to the outside during a road repair work, thereby the branch pipe 3 may be damaged by a machine such as excavator.